Easily synthesizable, spontaneously water-soluble, essentially voc-free, environmentally friendly (meth)acrylamido-functional siloxanol systems, process for preparation thereof and use

ABSTRACT

The invention relates to a composition and to a process for producing the composition comprising essentially water-soluble (meth)acrylamido-functional siloxanols, and to the use thereof.

This application is a Divisional of U.S. application Ser. No.14/395,750, which was filed on Oct. 20, 2014. U.S. application Ser. No.14/395,750 is a National Stage of PCT/EP2013/053651, which was filed onFeb. 25, 2013. This application is based upon and claims the benefit ofpriority to German Application No. 10 2012 206 510.5, which was filed onApr. 20, 2012.

The invention relates to a composition and to a process for producingthe composition comprising (meth)acrylamido-functional siloxanols,preferably essentially water-soluble (meth)acrylamido-functionalsiloxanols, and to the use thereof.

For the use of glass fibres in fibre composite materials, the glassfibre is frequently surface-treated with functionalized silanes. This iscommonly accomplished with the aid of aqueous slips in which theorganofunctional silane is dissolved. Depending on the chemical functionof the silanes, there may be a positive influence on the desiredproperties, for example fibre thickness or else cuttability(specifically for short fibre reinforcement). In this case, theorganofunctional silanes also make a significant contribution topromoting adhesion between the inorganic fibre and the organic resin.Even though application by means of aqueous slips is desirable, theorganofunctional silanes are still prepared in organic solvents.

For example, specific methacryloyl-functionalized silanes, for example3-methacryloyloxypropyltrimethoxysilane, are used in fibre compositematerials, examples being thermosets and thermoplastics, in order toincrease the performance of the fibre composite material. In otherapplications too, such as in filler modification, in coatings or inadhesives/sealants, these functionalized silanes are used as adhesionpromoter between organic and inorganic matrix.

A further application lies in the modification of specific properties,for example increasing the cuttability of glass fibres. Some compoundsused for that purpose are methacrylamidoalkylalkoxysilanes such as(RO)_(x)RSiNH(CO)C(CH₃)═CH₂ or else chromium(III) methacrylate chlorinecomplexes, for example Volan® from Du Pont (R═C1-C6 alkyl group).

In order to supply the compounds in aqueous slips, they must have goodwater solubility. The chromium-based methacrylate compounds exhibit goodwater solubility. However, they have the disadvantage of containingheavy metals. Methacrylamidoalkylalkoxysilane leads, in an aqueousmedium, to hydrolysis of the alkoxy groups and to release of thecorresponding alcohols methanol (toxic) and ethanol, and hence to theformation of VOCs (volatile organic compounds).

WO 00/75148 A1 (comparative example 1 here) describes a synthesisproceeding from aminopropyltriethoxysilane with a methacrylate in thepresence of dibutyltin oxide (DBTO). This reaction has a number ofdisadvantages: firstly, for a substantially complete conversion, a 100%excess of methacrylate is used, which has to be distilled off again.Thus, the space-time yield is poor. In addition, the reaction isconducted at high temperatures of 165-170° C., which results in problemsbecause of the tendency of acrylic acid to polymerize. To avoidpolymerization, a stabilizer has to be used. Catalysts used foressentially complete conversion are toxic, environmentally damagingorganotin compounds, for example dibutyltin oxide (DBTO). A furtherdisadvantage of this process is the costly and inconvenientrectification of the reaction product at high bottom temperatures andvery low absolute pressure. For this purpose, a further gas phasestabilizer has to be used in order to avoid polymerization in thecolumn. A heavy metal-containing residue remains in the bottoms, and hasto be disposed of separately. The distillation product, the commerciallyavailable product Y-5997 from Momentive(CH₃O)_(x)(C₂H₅O)_(3-x)Si(CH₂)₃NH(CO)C(CH₃)═CH₂, is virtuallywater-insoluble.

U.S. Pat. No. 3,249,461 describes the synthesis ofmethacrylamidopropylmethoxysilane by the reaction of methacryloylchloride in inert anhydrous solvents with aminopropyltrimethoxysilane. Adisadvantage in this process is the release of an equimolar amount ofhydrogen chloride, which has to be removed from the process in a costlyand inconvenient manner. In addition, the solvent content reduces thespace-time yield. The use of dinitrobenzene as a stabilizer is alsodisadvantageous.

The problem addressed by the present invention was that of providing(meth)acrylamido-functional organosilicon compounds, which are to haveexcellent water solubility, and should especially be spontaneouslysoluble in water. In addition, they should be particularly soenvironmentally friendly, especially preparable without heavy metalcatalysts and/or potentially harmful organic solvents. Equally, the useof stabilizers, as is necessary in the prior art, was to be reduced;more particularly, a process which manages without the use of gas phasestabilizers was to be developed. A further problem was to discover aprocess which allows preparation in the form of a one-pot reaction.Moreover, one problem was to widen the application spectrum of the(meth)acrylamido-functional organosilicon compounds to be provided, andto open them up to further advantageous applications. A further problemwas to better avoid the emission of organic solvents, especially toreduce that of the pure hydrocarbons, and preferably also to greatlyreduce VOC release in use as a result of hydrolysis of the alkoxyfunctions. Moreover, user application was to be distinctly simplified,in that the composition is applicable immediately, optionally after adilution, and is preferably itself storage-stable in aqueous solution,optionally after a dilution. A further problem addressed was therefore,in contrast to the prior art systems, to avoid the user having toobserve long initial preparation times using several components, i.e.addition of water and acid or the like, prior to the use of the(meth)acrylamido-functional organosilicon compounds, and instead beingable to use them immediately, optionally after spontaneous dilution inwater.

The problem was solved by a controlled aqueous conversion ofaminosilanes, especially of aminoalkylalkoxysilanes, preferably of di-and/or triaminoalkyl-functional silanes, in the presence of moisture oraqueous media (synonymous with: in the presence of water), morepreferably through hydrolysis and preferably condensation ofN-(2-aminoethyl)-3-aminopropyltrialkoxysilane and/or3-aminopropyltrialkoxysilane to oligomers, also referred to hereinafteras siloxanols for short, and reaction with an acrylic anhydride,especially (meth)acrylic anhydride, in an aqueous medium. Thewater-soluble acrylamido-functional siloxanols obtained are preferablyhydrolysed at least partly, more preferably fully, and optionallyessentially freed of alcohol (of hydrolysis). It is a great advantage ofthe invention that the acrylamido-functional siloxanols thus obtainedcan preferably be used in the form of a bottom product without furtherpurification. Thus, it is possible with the process according to theinvention and the inventive compositions containingacrylamido-functional siloxanes, to supply particularly economicallyviable and environmentally compatible products.

The invention provides a composition comprising acrylamido-functionalsiloxanols, especially essentially water-soluble acrylamido-functionalsiloxanols, derived from a

-   a) reaction of a component A which is an aminoalkyl-functionalized    silicon compound selected from    -   (i) an aminoalkyl-functional alkoxysilane or a mixture of        aminoalkyl-functional alkoxysilanes, each in the presence of a        defined amount of water, or    -   (ii) a hydrolysis or condensation product of at least one        aminoalkyl-functional alkoxysilane or    -   (iii) a mixture comprising at least one aminoalkyl-functional        alkoxysilane and a hydrolysis and/or condensation product of at        least one aminoalkyl-functional alkoxysilane,    -   with a component B which is an acrylic anhydride,        and optionally-   b) removal of at least a portion of the alcohol of hydrolysis, and    optionally of at least a portion of the water which was used in (i)    and optionally in (ii) or (iii), with optional addition of further    water in this step for removal of the alcohol of hydrolysis;    preferably, (ii) and (iii) were also prepared by reaction with a    defined amount of water.

It was found that, in the case of direct reaction of aminosilanes withacrylic anhydride, the unwanted transesterification products occur,since the methacrylic acid released reacts in a transesterificationreaction with the alkoxy groups in the aminosilane.

The inventors have surprisingly succeeded in avoiding these unwantedtransesterification reactions which occur in a reaction of aminosilaneswith (meth)acrylic anhydride. The unwanted transesterification can beavoided when, before the reaction with (meth)acrylic anhydride, theaminosilanes are oligomerized by hydrolysis and optionally condensationto siloxanes, preferably to siloxanols, with surprisingly successfulsubsequent acrylamide formation between the aminoalkyl-functionalsilicon compounds and the (meth)acrylic anhydride.

Preferably, for hydrolysis of the aminoalkyl-functional silanes, adefined amount of water is used, preferably between greater than orequal to 0.1 mol and 4.5 mol, especially between 0.1 and 2.0 mol, ofwater/mol of silicon atoms (inclusive), preferably between greater thanor equal to 0.3 mol and 1.5 mol of water/mol of silicon atoms in theaminoalkyl-functional silicon compounds, particular preference beinggiven to an amount of water between greater than or equal to 0.5 and 1.0mol of water/mol of silicon atoms.

The bottom temperature in the course of reaction with (meth)acrylicanhydride can be controlled via the rate of dropwise addition of(meth)acrylic anhydride. By cooling the reaction flask, it is possibleto achieve quicker addition of (meth)acrylic acid. The maximum possiblebottom temperature depends on the stabilizer system in the reactionmixture and the boiling point of the components used.

Essentially water-soluble substances are considered to beacrylamido-functional siloxanols which are water-soluble as such, andcan especially be dissolved or correspondingly mixed with water to anextent of at least 3 to 99.9% by weight. Preferred active ingredientconcentrations in water are between greater than or equal to 3 to 50% byweight in the overall composition, preferably between greater than orequal to 3 to 40% by weight; particularly preferred alternativeconcentration ranges are between greater than or equal to 3 to 10% byweight or else between 15 and 45% by weight. The acrylamido-functionalsiloxanols can be dissolved spontaneously in water and preferably formclear solutions. These solutions are storage-stable, for example over atleast three months in a closed vessel at 50° C. In accordance with analternative, however, acrylamido-functional siloxanols which can bebrought into solution by addition of acids, bases or buffers in theaqueous phase and preferably form clear solutions are also considered tobe water-soluble.

Particularly preferred compositions comprise acrylamido-functionalsiloxanols, especially essentially water-soluble acrylamido-functionalsiloxanols, which are derived from a reaction a) of a component A, anaminoalkyl-functionalized silicon compound selected from (ii) ahydrolysis and/or condensation product of at least oneaminoalkyl-functional alkoxysilane or (iii) a mixture comprising atleast one aminoalkyl-functional alkoxysilane and a hydrolysis and/orcondensation product of at least one aminoalkyl-functional alkoxysilanewith a component B which is an acrylic anhydride, especially of theformula IV, and optionally b) removal of at least a portion of thealcohol of hydrolysis, and optionally of at least a portion of thewater, with optional addition of further water in this step for removalof the alcohol of hydrolysis. Preferably, the acrylamido-functionalsiloxanols are admixed with water and the alcohol of hydrolysis isremoved until virtually complete hydrolysis of the alkoxy groups hasoccurred.

According to the invention, it is possible in principle to use anyaminoalkoxysilanes for preparation of the hydrolysates and condensatesand subsequent reaction with (meth)acrylic anhydride. For the desiredimproved solubility, preference is given to selecting aminosilaneshaving one primary and preferably at least one secondary amino group;these at least diamino-functional silanes lead to another improvement inthe solubility of the corresponding (meth)acrylamidoalkyl siloxanol. Itis an advantage of the additional secondary amino group that itneutralizes the (meth)acrylic acid released in the reaction to form acorresponding salt (aminohydro(meth)acrylate).

The aminohydro(meth)acrylate can be cleaved under basic conditions.Suitable bases are preferably basic alkali metal salts such as NaOH orKOH, preferably alkali metal alkoxides such as NaOR or KOR, preferablywhere R=alkyl-, preferably methyl-, and particular preference beinggiven to potassium methoxide.

Preferred aminoalkyl-functional alkoxysilanes correspond to the formulaI(R¹O)_(3−a−b)(R²)_(a)Si(B)_(1+b)  (I)

-   -   where the group B in formula I independently corresponds to a        group of the formula II        —(CH₂)_(c)—[(NH)(CH₂)_(d)]_(e)[(NH)](CH₂)_(f)]_(g)NH_((2−h))R³        _(h)  (II),    -   in formula I with R¹ independently a linear, branched or cyclic        alkyl group having 1 to 8 carbon atoms, especially having 1, 2,        3 or 4 carbon atoms, preferably methyl, ehtyl or propyl, and R²        independently a linear, branched or cyclic alkyl group having 1        to 8 carbon atoms, especially methyl, ethyl, propyl, n-butyl,        isobutyl, tert-butyl, pentyl, hexyl, heptyl or octyl, and in        formula II with R³ independently a linear, branched or cyclic        alkyl, aryl or alkylaryl group having 1 to 8 carbon atoms in        formula II, especially methyl, ethyl, butyl or benzyl, where h=0        is particularly preferred; and in formula I a is independently 0        or 1, b is independently 0, 1 or 2, b preferably being 0, and in        formula II c is independently selected from 1, 2, 3, 4, 5 and 6,        d is independently selected from 1, 2, 3, 4, 5 and 6, e is        independently selected from 0, 1, 2, 3, 4, 5 and 6, f is        independently selected from 1, 2, 3, 4, 5 and 6, g is        independently selected from 0, 1, 2, 3, 4, 5 and 6, and h is        independently 0 or 1; alternatively preferably e=g=0 or 1, and        d=f=2 or 3 and h=0 with c=3 and b=0 and a=0; particularly        preferred combinations are with R¹ being methyl or ethyl, a=0        and b=0 with c=3 and g, e and h each=0; alternatively likewise        preferably, a=0, b=0, c=3, e=1, d=1, 2 or 3, preferably d=2, and        g=0, h=0, for diamino-functional silanes,    -   or the B group corresponds to the formula III        —(CH₂)_(j)—NH_(2−p)(CH₂—CH₂—NH₂)_(p)  (III)    -   with j=1, 2 or 3 and p=0, 1 or 2, p preferably being selected        from 1 and 2; if appropriate, p may also be 0.

It is generally preferable when the aminoalkyl-functional alkoxysilanecorresponds to a diaminoalkyl-functional or a triaminoalkyl-functionalsilane, preferably a diaminoalkyl-functional or atriaminoalkyl-functional alkoxysilane of the formula I. Likewiseparticularly preferred are mixtures of the aforementioned silanes, suchas aminosilane with diaminosilane or else aminosilane withtriaminosilane or diaminosilane with triaminosilane, or else mixturescomprising three or more different aminosilanes of the formula I.

The acrylic anhydrides used are preferably methacrylic acid or(unsubstituted) acrylic anhydride, more preferably of the formula IV(CHR⁵═CR⁴CO)₂O  (IV)

-   -   where R⁴ is independently a hydrogen atom or a methyl group and        R⁵ is independently a hydrogen atom or a methyl group, R⁵        preferably being a hydrogen atom. Preference is given to        (CH₂═C(CH₃)CO)₂O and (CH₂═CHCO)₂O.

The inventive composition, which can be obtained from the conversion of(i), (ii) and/or (iii), can be represented in idealized form by thegeneral idealized formula V below for at least one essentiallywater-soluble acrylamido-functional siloxanol, where theacrylamido-functional siloxanols may preferably have linear, cyclic andcrosslinked structures,(R¹O)[(R¹O)_(1−a)(R²)_(a)Si(C)_(1+b)O]_(u)[(Y)Si(C)_(1+b)O]_(u′)R¹.(HX)_(z)  (V),where, in the general formula V,

-   -   C is an acrylamido group and    -   Y corresponds to OR¹ or, in crosslinked and/or        three-dimensionally crosslinked structures, independently to OR¹        or O_(1/2),    -   where R¹ corresponds essentially to hydrogen or some of R¹ may        optionally also independently be a linear, branched or cyclic        alkyl group having 1 to 8 carbon atoms, R¹ being an alkyl        preferably to an extent of less than 10 mol %, preferably less        than 5 mol %, more preferably less than 2 mol %, preferably less        than or equal to 1 mol %, and R² corresponds to a linear,        branched or cyclic alkyl group having 1 to 8 carbon atoms,        especially according to the definition of formula (I),    -   HX is an acid, where X is an inorganic or organic acid radical,    -   with each a independently 0 or 1, each b independently 0 or 1 or        independently additionally optionally 2, b preferably being 0,        with each u independently an integer greater than or equal to 2,        u′ greater than or equal to 0 and z greater than or equal to 0        and (u+u′)≧2, z especially being 0 or greater than or equal to        1, where z may preferably be less than to equal to the number of        secondary nitrogen atoms in the aminosilane used, and z may        likewise preferably be greater than the number of secondary        nitrogen atoms,    -   where the composition is essentially free of diluent, especially        organic solvents, more preferably of protic organic solvents,        and releases essentially no more alcohol in the course of        crosslinking.

Preferably, u on average is selected from an integer from 2 to 500,especially from 2 to 150, preferably from 2 to 80, including allnumerical values inbetween, such as 2, 3, 4, 5, 6, 7, 8, 9, 10, 15, 20,25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75 and 80, and in each case witha range of variation of up to plus/minus 5, u preferably being betweengreater than or equal to 20 and 80, more preferably between 20 and 60,preferably between greater than or equal to 20 and 40. In this context,independently thereof, u′ on average may be selected from an integerbetween 0 and 200, especially from 0 to 100, preferably from 0, 1, 2, 3,4, 5, 6, 7, 8, 9, 10, 15, 20, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80and 85, and in each case with a range of variation of up to plus/minus5, u′ preferably being between greater than or equal to 10 and 40,preferably 10 to 35. More preferably, the sum of (u+u′) together onaverage is between greater than or equal to 5 and 100, especiallybetween greater than or equal to 20 and 75, such as around 25 to 60.

A useful HX is acrylic acid or else any other organic or inorganic acidsuitable for the later use. It is generally possible to remove theacrylic acid present in the composition if required. It can preferablyremain in the composition, bound via hydrogen bonds or as a salt, andcontribute to crosslinking of the product, for example as a comonomer,in a later use.

Illustrative acrylamido groups (group C) on the silicon atoms of thesiloxanols are described as examples hereinafter, each on a siliconatom:≡Si—(CH₂)_(c)—[(NH)(CH₂)_(d)]_(e)[(NH)](CH₂)_(f)]_(g)NH_((1−h))R³_(h)—(CO)CR⁴═CHR⁵≡Si—(CH₂)_(j)—NH(CH₂—CH₂—NH)—(CO)CR⁴═CHR⁵≡Si—(CH₂)_(j)—NH_(2−p)(CH₂—CH₂—NH—(CO)CR⁴═CHR⁵)_(p)

In principle, an acrylamido group (group C), especially an acrylamidogroup of the siloxanols, is understood to mean all conceivableconversions of the aminoalkyl-functional groups mentioned with(meth)acrylic anhydride or CHR⁵═CR⁴(CO)—, but especially those formedfrom a reaction of an amino-functional group B according to the formulaII and/or III with an acrylic anhydride of the formula IV. Thus, a Cgroup may be selected from—(CH₂)_(c)—[(NH)(CH₂)_(d)]_(e)[(NH)](CH₂)_(f)]_(g)NH_((1−h))R³_(h)—(CO)CR⁴═CHR⁵,—(CH₂)_(j)—NH(CH₂—CH₂—NH)—(CO)CR⁴═CHR⁵ and—(CH₂)_(j)—NH_(2−p)(CH₂—CH₂—NH—(CO)CR⁴═CHR⁵)_(p).

The invention likewise provides a process for preparing a compositioncomprising acrylamido-functional siloxanols, especially essentiallywater-soluble acrylamido-functional siloxanols, and compositionsobtainable by this process, by

-   -   conducting the process in at least one step in the presence of        water, preferably of a defined amount of water, and    -   reacting a component A, an aminoalkyl-functional silicon        compound selected from:        -   (i) at least one aminoalkyl-functional alkoxysilane or a            mixture of aminoalkyl-functional alkoxysilanes of the            formula I, defined as above, or        -   (ii) a hydrolysis or condensation product of at least one            aminoalkyl-functional alkoxysilane of the formula I or        -   (iii) a mixture comprising at least one            aminoalkyl-functional alkoxysilane of the formula I and a            hydrolysis and/or condensation product of at least one            aminoalkyl-functional alkoxysilane of the formula I,    -   with a component B, an acrylic anhydride of the formula IV,        defined as above, especially methacrylic anhydride or the        (unsubstituted) acrylic anhydride, and optionally    -   at least partly removing the alcohol of hydrolysis formed in the        reaction.

Preferably, the reaction is conducted in the presence of a diluent,preference being given to an organic protic diluent such as alcohol.

It is preferable in this case when the defined amount of water isestablished in a process step prior to the step of reaction withcomponent B, especially for preparation of components A (ii) or (iii)from (i).

According to the invention, it is unnecessary to further purify thecompositions obtained; more particularly, a complex distillative workupof the acrylamido-functional siloxanols is unnecessary, since the bottomproducts can preferably be used directly. The inventive bottom productsdo not require any further purification because no disruptive catalystsor disruptive stabilizers are present in the bottom products.Consequently, the inventive compositions can be prepared in a much moreeconomically viable manner and with more environmentally compatiblestarting substances than described in the prior art.

It is a particular advantage of the process according to the inventionthat there is no need to use any gas phase stabilizers, as necessary inthe prior art, because the inventive process regime allows direct use ofthe composition in the form of the bottom product. A complexrectification of the products as in the prior art can be dispensed with.Consequently, the inventive compositions can be prepared in a much moreeconomically viable manner and with more environmentally compatiblestarting substances than described in the prior art.

It is a further advantage of the inventive compositions that they enableshorter preparation times on the part of the user prior to use. Thus,the user can bring the inventive composition to the desiredconcentration in a simple manner with water; it dissolves spontaneouslyand forms a clear solution. Simple stirring accelerates dissolution inwater. It is possible to dispense with the addition of furtherchemicals, as in the prior art, acid, etc.

In preferred embodiments, the process is preferably conducted with anaminoalkyl-functional silicon compound selected from anaminoalkyl-functional alkoxysilane of the formula I, or a hydrolysis orcondensation product of at least one aminoalkyl-functional alkoxysilaneof the formula I, or a mixture comprising at least oneaminoalkyl-functional alkoxysilane of the formula I and a hydrolysisand/or condensation product of at least one aminoalkyl-functionalalkoxysilane of the formula I, the hydrolysis and/or condensation of theaminoalkyl-functional alkoxysilane of the formula I being effected inthe presence of a defined amount of water, the defined amount of waterpreferably corresponding to 0.1 to 2.0 mol of water per mole of siliconatoms in the aminoalkyl-functional silicon compound used in the process,especially of the formula I, preferably 0.3 to 1.5 mol of water per moleof silicon atoms in the aforementioned silicon compound, more preferably0.5 to 1.0 mol of water per mole of silicon atoms in the siliconcompound; preferably, the defined amount of water is established in aprocess step prior to the step of the reaction with the component B andis preferably at least partly consumed by the hydrolysis.

In preferred embodiments, the process is preferably conducted with anaminoalkyl-functional alkoxysilane of the formula I, or a hydrolysis orcondensation product of at least one aminoalkyl-functional alkoxysilaneof the formula I or a mixture comprising at least oneaminoalkyl-functional alkoxysilane of the formula I and a hydrolysisand/or condensation product of at least one aminoalkyl-functionalalkoxysilane of the formula I

-   a) with R¹ independently methyl or ethyl and with a=0 and b=0 with    c=1, 2 or 3 and with the group B of the formula II with g=0 and e=1    and h=0, d=1, 2, 3, preferably d=2, or-   b) with R¹ independently methyl or ethyl and with a=0 and b=0 with    c=3 and with the group B of the formula II with g, e and h each 0    or, in an alternative, with a=0, b=0, c=3, and with the group B of    the formula II with e=1, d=1, 2, 3, preferably d=2 and with g=0, h=0    or with the group B of the formula II with e=g=0 or 1, and d=f=2 or    3 and h=0 with c=3 or with the group B of the formula III with j=3    and p=1 or 2, or-   c) with R¹ independently methyl or ethyl and with a=0 and b=0 with    c=2 and with the group B of the formula II with g, e and h each 0    or, in an alternative, with a=0, b=0, c=3, and with the group B of    the formula II with e=1, d=1, 2, 3, preferably d=2 and with g=0, h=0    or with the group B of the formula II with e=g=0 or 1, and d=f=2 or    3 and h=0 with c=2 or with the group B of the formula III with j=3    and p=1 or 2, or-   d) with R¹ independently methyl or ethyl and with a=0 and b=0 with    c=1 and with the group B of the formula II with g, e and h each 0    or, in an alternative, with a=0, b=0, c=3, and with the group B of    the formula II with e=1, d=1, 2, 3, preferably d=2 and with g=0, h=0    or with the group B of the formula II with e=g=0 or 1, and d=f=2 or    3 and h=0 with c=1 or with the group B of the formula III with j=3    and p=1 or 2.

It is likewise preferable when the process is preferably conducted withan aminoalkyl-functional alkoxysilane, or a hydrolysis or condensationproduct of at least one aminoalkyl-functional alkoxysilane or a mixturecomprising at least one aminoalkyl-functional alkoxysilane and ahydrolysis and/or condensation product from at least oneaminoalkyl-functional alkoxysilane selected from the followingaminoalkyl-functional alkoxysilanes, especially of the general formulaI: 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane:3-aminopropylmethyldimethoxysilane, 3-aminopropylmethyldiethoxysilane,1-aminomethyltrimethoxysilane, 1-aminomethyltriethoxysilane,2-aminoethyltrimethoxysilane, 2-aminoethyltriethoxysilane,3-aminoisobutyltrimethoxysilane, 3-aminoisobutyltriethoxysilane,N-n-butyl-3-aminopropyltriethoxysilane,N-n-butyl-3-aminopropylmethyldiethoxysilane,N-n-butyl-3-aminopropyltrimethoxysilane,N-n-butyl-3-aminopropylmethyldimethoxysilane,N-n-butyl-1-aminomethyltriethoxysilane,N-n-butyl-1-aminomethylmethyldimethoxysilane,N-n-butyl-1-aminomethyltrimethoxysilane,N-n-butyl-1-aminomethylmethyltriethoxysilane,benzyl-3-aminopropyltrimethoxysilane,benzyl-3-aminopropyltriethoxysilane,benzyl-2-aminoethyl-3-aminopropyltrimethoxysilane,benzyl-2-aminoethyl-3-aminopropyltriethoxysilane,diaminoethylene-3-propyltrimethoxysilane,diaminoethylene-3-propyltriethoxysilane,triaminodiethylene-3-propyltrimethoxysilane,triaminodiethylene-3-propyltriethoxysilane,(2-aminoethylamino)ethyltrimethoxysilane,(2-aminoethylamino)ethyltriethoxysilane,(1-aminoethylamino)methyltrimethoxysilane and(1-aminoethylamino)methyltriethoxysilane, preference being givenespecially to di- and/or triaminoalkoxysilanes. Particular preference isgiven to diaminoethylene-3-propyltrimethoxysilane,diaminoethylene-3-propyltriethoxysilane,triaminodiethylene-3-propyltrimethoxysilane,triaminodiethylene-3-propyltriethoxysilane.

It is additionally particularly preferable when the process is conductedin at least one step in the presence of a defined amount of water; moreparticularly as follows:

-   -   component A, an aminoalkyl-functional silicon compound selected        from: (i) at least one aminoalkyl-functional alkoxysilane or a        mixture of aminoalkyl-functional alkoxysilanes of the formula I,        defined as above, is reacted with a defined amount of water or        water in excess or (ii) a hydrolysis or condensation product of        at least one aminoalkyl-functional alkoxysilane of the formula I        is prepared from the aminoalkyl-functional alkoxysilane of the        formula I in the presence of a defined amount of water, (iii) a        mixture comprising at least one aminoalkyl-functional        alkoxysilane of the formula I and a hydrolysis and/or        condensation product of at least one aminoalkyl-functional        alkoxysilane of the formula I, is prepared from the        aminoalkyl-functional alkoxysilane in the presence of a defined        amount of water, and

-   b) subsequently reacted with a component B, an acrylic anhydride of    the formula IV, defined as above, especially methacrylic anhydride    or the (unsubstituted) acrylic anhydride, and

-   c) optionally, the alcohol of hydrolysis formed in the reaction is    at least partly removed.

In further preferred process variants, preference is given to processescomprising

-   -   in a step (I) comprising the component steps which follow,        admixing component A, an aminoalkyl-functional silicon compound,        which is preferably at least one aminoalkyl-functional        alkoxysilane of the formula I as defined above, optionally in a        mixture with a diluent, especially organic protic diluents,        preferably an alcohol, more preferably methanol, ethanol or        propanol,    -   with a defined amount of water, preference being given to        continuous or discontinuous metered addition of water;        preferably 0.5 to 1.5 mol and more preferably 0.5 to 1.0 mol of        water per mole of silicon atoms in the silicon compound are        metered in; preferably within a defined period, and preferably        with stirring, preference within the temperature range of 0 to        75° C., especially 30 to 75° C., preferably between 40 and 65°        C., more preferably between 50 and 65° C., for between 10        minutes and 10 hours, preferably between 10 minutes and 5 hours,        more preferably between 10 minutes and 2.5 hours, and    -   optionally at least partly removing the alcohol of hydrolysis        and/or the added diluent, preferably the alcohol added, and    -   adding the acrylic anhydride of the formula IV to the resulting        mixture, especially at a temperature of the mixture between 0        and 30° C., preferably metering in the acrylic anhydride of the        formula IV such that the temperature of the mixture does not        rise above 75° C., and    -   optionally adding a stabilizer to the mixture, and, in step II,        alternatively, conducting step (IIa) or step (IIb), wherein    -   in a step (IIa), in an alternative, after step (I), at least        partly removing the alcohol of hydrolysis and/or the added        diluent under ambient or reduced pressure and elevated        temperature, preference being given to adding water in step        (IIa), and water can especially be added before, during and        after further addition of diluent, or    -   in a step (IIb), in a further alternative, after step (I),        adding a base to the mixture, especially when the acrylic        anhydride is present in a molar excess relative to the primary        amino groups of the aminoalkyl-functional silane, preferably a        base which forms a salt with acrylic acid which is sparingly        soluble in water or in the alcoholic-aqueous phase, for example        a metal salt, alkaline earth metal hydroxide, alkaline earth        metal oxide or alkali metal hydroxide, and optionally    -   removing the precipitate, especially the sparingly soluble salt        of the acrylate, optionally    -   adding an organic acid and at least partly removing the alcohol        of hydrolysis and/or the diluent and optionally removing at        least a portion of the water, with optional addition of further        water for removal of the alcohol of hydrolysis in this step. The        composition thus obtained can be used directly; preferably, it        is adjusted with water to the desired active ingredient content        of acrylamido-functional siloxanol. Formation of sparingly        soluble salts can also be accomplished by using alkali metal or        alkaline earth metal hydroxides or oxides such as calcium        hydroxide, calcium oxide, but it is also possible to use sodium        hydroxide/oxide. In general, the salts of Ca, Mg, Ba, Sr, Al        and/or zinc can be used to form sparingly soluble salts.

Useful diluents generally include all suitable diluents, such as organicaprotic or protic diluents and mixtures of these, examples beingalcohols, ethers or ketones, ethyl acetate, methylene chloride,preference being given to organic protic diluents or, for dilution ofthe composition prepared, water. The alcohol (of hydrolysis) alreadypresent as a diluent and/or formed in the reaction is removedsubstantially, preferably completely, in all process variants accordingto the invention. The distillative removal of the alcohol is carried outpreferably under reduced pressure. Alternatively, until an alcoholcontent of less than 20% by weight to 0.0001% by weight, preferably lessthan or equal to 12% by weight, more preferably less than or equal to 5%by weight, especially preferably less than or equal to 3.0% by weight,even more preferably less than or equal to 1.0% by weight, especiallyless than or equal to 0.5% by weight is detected, or down to the currentanalytical detection limit. Generally speaking, the resultingcomposition of the invention is then substantially solvent-free, moreparticularly alcohol-free. The composition obtained accordinglypreferably corresponds directly to the composition of the invention, andpreferably need not itself be further purified.

It is especially preferable when the volatile diluent and the alcohol ofhydrolysis are removed down to a content in the overall composition ofless than or equal to 12% by weight to 0% by weight, preferably to lessthan or equal to 10% by weight, more preferably less than or equal to 5%by weight, even more preferably less than or equal to 2% by weight to0.0001% by weight, especially less than or equal to 1 to 0.0001% byweight, the removal preferably being effected by distillation,especially under reduced pressure in the range from 1 to 1000 mbar,preferably from 0.001 to 350 mbar, more preferably between 0.001 and 250mbar, at a mild temperature of bottom temperature less than 60° C.,especially less than 55° C.

Preferably, in the process, the molar ratio of the nitrogen atoms in theaminoalkyl-functional silicon compound, especially in theaminoalkyl-functional silanes of the formula I, to the molar ratio ofthe CHR⁵═CR⁴(CO)— acryloylcarbonyl function released from the acrylicanhydride of the formula IV is in the range from 1:5 to 5:1, especially1:2 to 2:1, preferably 1:1.5 to 1.5:1, more preferably 1:1 with a rangeof variation of plus/minus 0.5, preferably plus/minus 0.2.

Alternatively, it may be particularly preferable to use adiaminoalkyl-functional silane in an equimolar amount with acrylicanhydride of the formula IV. The function of the secondary aminefunction here is to neutralize the free acrylic acid, and can react togive an aminohydro(meth)acrylate, which can especially be cleavedsubsequently under basic conditions.

Preference is further given to a process wherein the active ingredientcontent of acrylamido-functional siloxanols is adjusted to 0.0001 to99.9% by weight in the overall composition, especially to 10 to 80% byweight, preferably to 20 to 60% by weight, more preferably to 35 to 60%by weight, where the active ingredient content can be adjusted to anyvalue between 99.99% by weight and 0.00001% by weight by dilution with adiluent, preferably with water or optionally with aqueous alcohols orany other suitable diluent.

It is likewise possible to add customary acids, bases, additives,auxiliaries, fillers, stabilizers, pigments, to adjust the productproperties or the colour, or to increase storage stability.

The process according to the invention affords compositions generallyhaving pH values, after the removal of the diluent, alcohol ofhydrolysis and at least portions of water, having a value between 3 and11, preferably between 5 and 11, especially between 6 and 10, morepreferably between 6 and 8, especially preferably between 7 and 8, orbetween 6.5 and 8.0 or between 8 and 10. It is particularly preferablein this context when the compositions produced comprise(meth)acrylamidoalkyl-functional siloxanols which have good watersolubility without modification of the pH. These compositions thentypically have a pH of 6 to 9.

Additionally or alternatively, the pH of the composition can be adjustedby adding an acid or base. Preferably, the pH of a composition can beadjusted to a pH below 8 in the aqueous phase, more preferably between 3and 8, especially between 3 and 6, preferably between 3 and 5.5, morepreferably between 3 and 5.0. Typical acids for adjusting the pH may bemineral acid such as HCl, sulphuric acid or else organic acids,preference being given to organic acids such as acetic acid, lactic acidor formic acid.

The preparation process likewise has an advantageous effect on theviscosity of the compositions. Thus, the inventive compositions preparedare high-mobility liquids of a viscosity which allows easy processing,simple transfer and measurement. The viscosity of thecompositions—prepared as the bottom product—is between 1 mPas and 2000mPas, preferably between 1 and 1500 mPas, further preferably between 1and 400 mPas.

The invention likewise provides compositions obtainable by anaforementioned process and comprising acrylamido-functional siloxanols,preferably essentially water-soluble acrylamido-functional siloxanols,especially acrylamido-functional siloxanols which have been at leastpartly to preferably essentially fully hydrolysed, the compositionfurther comprising amlamidoalkyl-aminoalkyl-functional siloxanols andoptionally acrylamidoalkyl-aminoalkyl-functional silanols.

The invention further provides for the use of a composition and of theprocess products as an adhesion promoter, for functionalization ofglass, especially for functionalization of glass fibres, formodification of fillers, pigments and/or inorganic surfaces, especiallyas a filler coating, coating of pigments, coating of inorganic surfaces,in dental impression compounds, in dental polymer compounds, as anadditive in polymers, in adhesives, in sealants, in fibre compositematerials, together with polymers, especially thermoplastics,thermosets, elastomers, for functionalization of polymers, for adjustingthe hydrophilicity of polymers. Particular preference is given to usefor production of aqueous systems comprising the inventiveacrylamido-functional siloxanols, or materials, articles and/or productsmodified thereby.

The example which follows illustrates the process according to theinvention in detail without limiting the invention to this example.

Determination Methods:

The alcohol content after hydrolysis is determined by gas chromatography(% by weight). SiO₂ content of organic silicon compounds: determined byprocesses known to those skilled in the art, for example oxidation ofthe organic constituents, followed by calcination, hydrofluoric acidfuming and determination of the weight difference (%=% by weight).

Determination of nitrogen: By a method known to those skilled in theart, for example according to Kjeldahl. Turbidity: DIN EN ISO 7027, withinstrument from HACH Lange, model 2100 ISO.

Compounds Used:

“TEMPO (=2,2,6,6-tetramethylpiperidinyloxy free radical)” and“4-hydroxyTEMPO”;

“SANTONOX (Flexsys America, Akron, Ohio) antioxidant 4,4′-thio-bis(6-t-butyl-m-cresol)”

EXAMPLE 1

A 500 ml stirred apparatus with distillation system was initiallycharged with 156.00 g of N-(3-(trimethoxysilyl)propyl)ethylenediamine(0.70 mol) and 40.20 g of methanol. 9.52 g of demineralized water (0.53mol) were added dropwise within 6 minutes while stirring. In the courseof this, the bottom temperature rose to 47.8° C. The mixture was stirredat a bottom temperature of 54° C. to 59° C. for a further 2 hours. At abottom temperature of 23.1° C., 107.9 g of methacrylic anhydride (0.70mol) were added dropwise within 2 hours. In the course of this, thebottom temperature rose to max. 51.7° C. 0.02 g of 4-hydroxy-tempo wasadded to the bottoms as an additional stabilizer. Subsequently, 30.21 gof distillate were removed at an absolute pressure of about 200 mbar anda bottom temperature of about 40° C. The methanol content of thedistillate was 98.3 area % (GC-TCD determination). The viscosity in thebottoms distinctly increased. For further analysis, 78.1 g of samplewere taken from the bottoms. Subsequently, at a bottom temperature of32.2° C., 99.61 g of water were added within two minutes. In the courseof this, the bottom temperature rose to 36.3° C. 45.2 g ofmethanol/water mixture were distilled off at an absolute pressure of 200mbar and a bottom temperature of about 49° C. Subsequently, 120.02 g ofwater were stirred in, and 106.02 g of methanol/water mixture weredistilled off at an absolute pressure of 200 mbar to 128 mbar. A clear,slightly viscous, yellowish liquid was obtained as the bottom product.Yield: 227.9 g. As can be seen in Table 1, the product has a solidscontent of 54.6%.

TABLE 1 Analysis results for the bottom product from Example 1Determination Method Result Total N [%] see above 5.2 Solids content [%]3 g/3 hours/105° C. 54.6 SiO₂ content [%] see above 11.6 pH DIN ISO 49257.7 Density [g/cm³] DIN 51757 1.142 Viscosity [mPa · s] DIN 53015 351Free methanol [%] see above 0.1 ¹H and ¹³C NMR The singly convertedoligomerized target product was found. Amidation has been effected atthe primary amine.

EXAMPLE 2

An 8 I stirred apparatus with distillation system was initially chargedwith 2490.58 g of N-(3-(trimethoxysilyl)propyl)ethylenediamine (11.2mol) and 640.92 g of methanol. 161.54 g of demineralized water (8.96mol) were added dropwise within 11 minutes while stirring. In the courseof this, the bottom temperature rose to 54.7° C. The mixture was stirredat a bottom temperature of 51° C. to 56° C. for a further 0.8 hour. At abottom temperature of 36.3° C., a solution of 1727.24 g of methacrylicanhydride (11.2 mol) and 3.40 g of 4-hydroxy-tempo was then metered inwithin 2.4 hours. In the course of this, the bottom temperature rose tomax. 53.6° C. The bottoms remained clear and colourless. Subsequently,2400.32 g of demineralized water were metered in within 14 minutes. Freemethanol was distilled off at an absolute pressure of about 200 mbar to112 mbar. The bottom temperature during the distillation was 46.0° C. to52.2° C. The total amount of distillate was 2819.3 g. During thedistillation, a total of 3699.72 g of demineralized water were added infour portions. A clear, only slightly yellowish, low-viscosity liquidwas obtained as the bottom product. Yield: 8082.3 g. As can be seen inTable 2, the product has a solids content of 40.6%.

TABLE 2 Analysis results for the bottom product from Example 2Determination Method Result Total N [%] see above 4.1 Solids content [%]3 g/3 hours/105° C. 40.6 SiO₂ content [%] see above 8.3 pH DIN ISO 49257.1 Density [g/cm³] DIN 51757 1.097 Viscosity [mPa · s] DIN 53015 20Free methanol [%] see above 1.4 ¹H and ¹³C NMR The singly convertedoligomerized target product was found. Amidation has been effected atthe primary amine.

COMPARATIVE EXAMPLE 1 (comparative example for WO 00/75148 A1)

A 1 I stirred apparatus with distillation system was initially chargedwith 398.07 g of aminopropyltriethoxysilane (1.8 mol), and 1.99 g ofdibutyltin oxide, 0.037 g of ionol and 0.18 g of4,4′-thiobis(6-tert-butyl-m-cresol) were stirred in. Subsequently,within 2 hours, a mixture of 360.35 g of methyl methacrylate (3.60 mol)and 5.41 g of dipropylamine was metered in at a bottom temperature of152.8° C. to 165.5° C. After a reaction time of 0.3 hour, at a toptemperature of 76.5° C. to 80.4° C., a mixture of methanol, ethanol,methyl methacrylate and ethyl methacrylate was removed. After adistillation time of 2.5 hours, at an absolute pressure of 316 mbar to<1 mbar and a bottom temperature of 157.2° C., residual amounts of lowboilers were removed from the bottom product. A total of 287.8 g ofdistillate was removed. 461.35 g of pale yellowish and low-viscosityliquid were obtained as the bottom product. In accordance with thedisclosure of WO 00/75148 A1, the crude methacrylic product is distilledunder high vacuum. For the purposes of determining the solubility, itwas entirely sufficient to use the crude product that still containsdibutyltin oxide. For later use, a rectification disclosed by WO00/75148 A1 would be necessary.

TABLE 3 Analysis results from Comparative Example 1 Determination MethodResult Total N [%] see above 5.0 SiO₂ content [%] see above 22.0 Freemethanol [%] see above 0.1 pH DIN ISO 4925 9.7 Viscosity [mPa · s] DIN53015 50.1Solubility Characteristics:

Table 4 shows the solubility characteristics as a function of theaminosilane used in the reaction with methacrylic anhydride. Bottomproducts from Example 1 and Example 2 show good solubility (dissolvespontaneously within a few seconds and lead to clear mixtures) even inthe case of direct dissolution in demineralized water (without additionof acetic acid). The bottom product from Example 2 shows good solubilitycharacteristics even at distinctly increased concentrations. Incomparison, the product from Comparative Example 1, and also thecommercially available Y-5997 (Momentive Performance Materials, mixtureof 2-methacrylamidoalkoxypropylsilane having ethoxy and methoxy groupsas alkoxy groups), does not dissolve in demineralized water (Table 6).Only at low pH values does this product show solubility after vigorousstirring for 10 minutes (Table 7).

TABLE 4 Overview of the solubility tests of the bottom products (3.0%bottom product in demineralized water) pH Turbidity [FNU] Bottom product(hydro- after after after from Example lysate) 1 min. 1 h 24 h 1(reactant: 7.3 clear clear clear N-(3-(tri- (0.3 FNU) (0.5 FNU) -methoxysilyl)propyl)- after storage ethylenediamine at RT for 6 d 14.1¹⁾ clear clear clear (0.3 FNU) (1.0 FNU) - after storage at RT for 7d 2 (reactant: 5.4¹⁾ clear clear clear N-(3-(tri- (1.1 FNU) (0.9 FNU)methoxysilyl)propyl) ethylene-diamine ¹⁾The pH of the hydrolysate wasadjusted by addition of acetic acid.

TABLE 5 Overview of the solubility tests on the bottom product fromExample 2 Hydrolysate w(bottom product) w(H₂O) Turbidity [FNU] [%] [%]pH 1 min. 24 h 6 94 6.8 0.7 (clear) 0.6 (clear) 12 88 6.7 0.9 (clear)0.9 (clear) * w = weight

TABLE 6 Solubility of 3% of the product from Comparative Example 1 andY-5997 in demineralized water pH Turbidity [FNU] (hydro- after afterafter Product lysate) 10 min. 1 h 24 h Y-5997 9.1 not turbid/ turbid/dissolved precipitates precipitates From not not turbid/ turbid/ Example3 determined dissolved precipitates precipitates

TABLE 7 Solubility of 3% Y-5997 in demineralized water. The pH of thehydrolysate was adjusted by addition of acetic acid. pH Turbidity [FNU](hydro- after after after after lysate) 1 min. 10 min. 1 h 24 h 4.1turbid clear clear clear (0.3 TE/F) (1.7 FNU) - after storage at RT for7 dVOC Release as a Function of Active Ingredient Concentration:

As is apparent in Table 8, Y-5997 has a maximum VOC release of 18% at a40% active ingredient concentration. The methacrylamidopropylsiloxanolfrom Example 2 releases only max. 1.4% VOC at the same active ingredientconcentration.

TABLE 8 comparison of maximum VOC release as a function of activeingredient concentration VOC [w/w %] Active ingredient Methacrylamido-concentration propylsiloxane [w/w %] Y-5997 from Example 2 40 18 1.4 209.0 0.7 3 1.35 0.11 * w = weight

TABLE 9 Calculation of maximum VOC release Methacrylamido-propylsiloxane Determination Method Unit from Example 2 Y-5997 Methanolafter see above w/w % 1.4 34 hydrolysis Ethanol after see above w/w %<0.1 11 hydrolysis VOC Sum total of w/w % 1.4 45 methanol/ethanol afterhydrolysis * w = weightSolubility and Maximum VOC Release as a Function of Active IngredientConcentration:

As apparent in Table 10, Y-5997 shows poor solubility at relatively highactive ingredient concentrations in water/acetic acid. The addition ofacetic acid helps to dissolve the Y-5997 at low active ingredientconcentrations in water. For this purpose, however, the hydrolysate hasto be stirred vigorously for 8 minutes. Themethacrylamidopropylsiloxanol from Example 2 shows spontaneoussolubility even at a high active ingredient concentration. Addition ofacetic acid is unnecessary (see Table 11).

TABLE 10 Solubility and maximum VOC release from Y-5997 as a function ofactive ingredient concentration Active ingredient concentration VOC [w/w%] [w/w %] Dissolution characteristics 40 18 Product is insoluble indemineralized water. However, the hydrolysate still remains distinctlyturbid in 1.50% acetic acid. 20 9.0 Product is insoluble indemineralized water. However, the hydrolysate still remains distinctlyturbid in 1.50% acetic acid. 3 1.35 A clear hydrolysate is obtained in1.50% acetic acid after vigorous stirring for 8 min. * w = weight

TABLE 11 Solubility and maximum VOC release frommethacrylamidopropylsiloxanol (Example 2) as a function of activeingredient concentration: Active ingredient concentration VOC [w/w %][w/w %] Dissolution characteristics 40 1.40 Product was not diluted 200.70 Dissolves spontaneously in water: clear liquid, unchanged after 4 d8 0.28 Dissolves spontaneously in water: clear liquid, unchanged after 4d 3 0.11 Dissolves spontaneously in water: clear liquid, unchanged after4 d * w = “weight”

EXAMPLE 3

A 1 I stirred apparatus with distillation system was initially chargedwith 251.08 g of Dynasylan® TRIAMO (4,7,10-triazadecyltrimethoxysilane,1.0 mol) and 80.00 g of methanol. 14.42 g of demineralized water (0.8mol) were added dropwise within 2 minutes while stirring. In the courseof this, the bottom temperature rose from 36.8° C. to 41.5° C. Themixture was stirred at a bottom temperature of 63-65° C. for a further 1hour. Subsequently, the bottoms were cooled to 26.5° C., and 215.84 g ofmethacrylic anhydride (1.0 mol) were metered in within 1.5 hours. In thecourse of this, the bottom temperature rose to max. 56.0° C. 0.42 g of4-hydroxy-tempo was added to the bottoms as an additional stabilizer(prior to the addition of methacrylic anhydride). A bottoms sample (35.0g) was taken for analytical studies. 300.34 g of demineralized waterwere metered into the bottoms within 3 minutes. 430.5 g of distillate(methanol/water mixture) were removed at an absolute pressure of about180 mbar and a bottom temperature of about 42° C. During thedistillation, a total of 451.18 g of demineralized water were stirredinto the bottoms. At the end of the distillation, the bottom temperaturewas 52° C. at an absolute pressure of 100 mbar. A clear, pale yellowishliquid was obtained as the bottom product.

Yield: 818.7 g

As can be seen from Table 12, the product has a solids content of 39.1%.It dissolves spontaneously in water (see Table 13).

TABLE 12 Analysis results for Example 3 Determination Method ResultTotal N [%] see above 4.2 Solids content [%] 3 g/8 hours/125° C. 39.1SiO2 content [%] AN-SAA 1171 6.7 pH DIN ISO 4925 6.1 Density [g/cm³] DIN51757 1.106 Viscosity [mPa · s] DIN 53015 180 Free methanol [%] Based onSAA0272 0.2 1H and 13C NMR Conversion level of the amidation: about 80mol %; target product present as oligomer

TABLE 13 Overview of the solubility tests for Example 3 Hydrolysatew(bottom product) w(H2O) Turbidity [FNU] [%] [%] pH 1 min. 24 h 6 94 6.82.9 (clear) 1.6 (clear) 12 88 6.7 3.1 (clear) 2.7 (clear) Hydrolysatew(bottom product) w(0.5% acetic acid) Turbidity [FNU] [%] [%] pH 1 min.24 h 6 94 5.1 1.7 (clear) 1.7 (clear) 12 88 4.2 1.7 (clear) 2.6 (clear)

EXAMPLE 4

A 1 I stirred apparatus with distillation system was initially chargedwith 332.07 g of 3-aminopropyltriethoxysilane (1.50 mol) and 81.04 g ofethanol. 21.6 g of demineralized water (1.2 mol) were added dropwisewithin 3 minutes while stirring. In the course of this, the bottomtemperature rose from 32.3° C. to 33.5° C. The mixture was stirred at abottom temperature of about 60° C. for a further 1 hour. Subsequently,the bottoms were cooled to 28.9° C., and 77.1 g of methacrylic anhydride(0.5 mol) were metered in within 36 minutes. In the course of this, thebottom temperature rose to max. 54° C. 0.42 g of 4-hydroxy-tempo wasadded to the bottoms as an additional stabilizer (prior to the additionof methacrylic anhydride). 300.11 g of demineralized water were meteredinto the bottoms within 3 minutes. For analytical studies, a bottomssample (56.3 g) was taken. By adding 27.30 g of glacial acetic acid, apH of about 7.9 was obtained. 390.9 g of distillate (ethanol/watermixture) were removed at an absolute pressure of about 146 mbar and abottom temperature of about 40° C. During the distillation, a total of50 g of demineralized water and 121.6 g of glacial acetic acid werestirred into the bottoms. At the end of the distillation, the bottomtemperature was 50° C. at an absolute pressure of 170 mbar. The bottomproduct obtained was a slightly turbid, yellowish liquid, which wasfiltered through a pressure filter.

Yield; 531.6 g of yellowish, slightly turbid liquid.

The product dissolves spontaneously in water.

TABLE 14 Analysis result for Example 4 Determination Method Result TotalN [%] see above 3.4 Solids content [%] 3 g/19 hours/125° C. 42.4 SiO2content [%] AN-SAA 1171 14.7 pH DIN ISO 4925 4.4 Density [g/cm³] DIN51757 1.145 Viscosity [mPa · s] DIN 53015 76 Ethanol after hydrolysis[%] Based on SAA0272 1.6 1H and 13C NMR Conversion level of theamidation: >90 mol %, target product present as oligomer

The invention claimed is:
 1. A composition, comprising at least onewater-soluble acrylamido-functional siloxanol oligomer of formula (V):(R¹O)[(R¹O)_(1−a)(R²)_(a)Si(C)_(1+b)O]_(u)[(Y)Si(C)_(1+b)O]_(u′)R¹.(HX)z  (V), obtained by: a) reacting a component A with an acrylic anhydride(B); and optionally b) removing at least a portion of hydrolyzedalcohol, with optional addition of water for removal of the hydrolyzedalcohol, wherein: the component A is at least oneaminoalkyl-functionalized silicon compound selected from the groupconsisting of (i) an aminoalkyl-functional alkoxysilane or a mixture ofaminoalkyl-functional alkoxysilanes, each in the presence of water, (ii)a hydrolysis or condensation product of at least oneaminoalkyl-functional alkoxysilane, and (iii) a mixture comprising atleast one aminoalkyl-functional alkoxysilane and a hydrolysis product, acondensation product, or both, of the at least one aminoalkyl-functionalalkoxysilane:, C represents an acrylamido group; Y represents OR¹ or, incrosslinked and/or three-dimensionally crosslinked structures,independently to OR¹ or O_(1/2); R¹ represents hydrogen; R² represents alinear, branched or cyclic alkyl group having 1 to 8 carbon atoms; HX isan acid, where X is an inorganic or organic acid radical; a is 0 or 1; bis 0 or 1; u is an integer greater than or equal to 2; u′ is greaterthan or equal to 1; z is greater than or equal to 0; (u +u′) is greaterthan or equal to 2; and the composition is essentially free of diluentsand releases essentially no alcohol during a crosslinking.
 2. Thecomposition according to claim 1, wherein: the aminoalkyl-functionalalkoxysilane is defined by formula (I):(R¹O)_(3−a−b)(R²)_(a)Si(B)_(1+b)  (I); B independently represents agroup of formula (II):—(CH₂)_(c)—[(NH)(CH₂)_(d)]_(e)[(NH)](CH₂)_(f)]_(g)NH_((2−h))R³_(h)  (II), R¹ are each independently a linear, branched or cyclic alkylgroup having 1 to 8 carbon atoms, R² are each independently a linear,branched or cyclic alkyl group having 1 to 8 carbon atoms, R³ are eachindependently a linear, branched or cyclic alkyl, aryl or alkylarylgroup having 1 to 8 carbon atoms, a is 0 or 1, b is 0, 1 or 2, c is 1,2, 3, 4, 5 or 6, d is 1, 2, 3, 4, 5 or 6, e is 0, 1, 2, 3, 4, 5 or 6, fis 1, 2, 3, 4, 5 or 6, g is 0, 1, 2, 3, 4, 5 and 6, and h isindependently 0 or 1, or B is of formula (III):—(CH₂)_(j)—NH_(2−p)(CH₂—CH₂—NH₂)_(p)  (III), j is 1, 2 or 3, and p is 0,1 or
 2. 3. The composition according to claim 1, wherein: the acrylicanhydride is of formula (IV):(CHR⁵═CR⁴CO)₂O  (IV); R⁴ are each independently a hydrogen atom or amethyl group; and R⁵ are each independently a hydrogen atom or a methylgroup.
 4. An article, comprising the composition according to claim 1,wherein the article is selected from the group consisting of an adhesionpromoter, a dental impression compound, a polymer additive, an adhesive,a sealant, and a fiber composite material.
 5. The composition accordingto claim 1, wherein C is selected from the group consisting of—(CH₂)_(c)—[(NH)(CH₂)_(d)]_(e)[(NH)](CH₂)_(f)]_(g)NH_((1−h))R³_(h)—(CO)CR⁴═CHR⁵,—(CH₂)_(j)—NH(CH₂—CH₂—NH)—(CO)CR⁴═CHR⁵, and—(CH₂)_(j)—NH_(2−p)(CH₂—CH₂—NH—(CO)CR⁴═CHR⁵)_(p), wherein: c 1, 2, 3, 4,5 or 6; d 1, 2, 3, 4, 5 or 6; e 0, 1, 2, 3, 4, 5 or 6; f 1, 2, 3, 4, 5or 6; g 0, 1, 2, 3, 4, 5 or 6; h 0 or 1; j 1, 2 or 3; p 0, 1 or 2; R³ isa linear, branched or cyclic alkyl, aryl or alkylaryl group having 1 to8 carbon atoms; and R⁵ a hydrogen atom or a methyl group.